/*
 * Copyright (c) 2017, 2018, Oracle and/or its affiliates.
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 * All rights reserved.
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 * Redistribution and use in source and binary forms, with or without modification, are
 * permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice, this list of
 * conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright notice, this list of
 * conditions and the following disclaimer in the documentation and/or other materials provided
 * with the distribution.
 *
 * 3. Neither the name of the copyright holder nor the names of its contributors may be used to
 * endorse or promote products derived from this software without specific prior written
 * permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS
 * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
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 * COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
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package com.oracle.truffle.llvm.parser.metadata.debuginfo;

import com.oracle.truffle.llvm.parser.metadata.MDBaseNode;
import com.oracle.truffle.llvm.parser.metadata.MDGlobalVariable;
import com.oracle.truffle.llvm.parser.metadata.MDGlobalVariableExpression;
import com.oracle.truffle.llvm.parser.metadata.MDValue;
import com.oracle.truffle.llvm.parser.metadata.MetadataVisitor;
import com.oracle.truffle.llvm.parser.model.SymbolImpl;

final class MDSymbolExtractor implements MetadataVisitor {

    private static final SymbolImpl DEFAULT_SYMBOL = null;

    static SymbolImpl getSymbol(MDBaseNode container) {
        if (container == null) {
            return DEFAULT_SYMBOL;
        }

        final MDSymbolExtractor visitor = new MDSymbolExtractor();
        container.accept(visitor);
        return visitor.sym;
    }

    private MDSymbolExtractor() {
    }

    private SymbolImpl sym = DEFAULT_SYMBOL;

    @Override
    public void visit(MDValue mdVal) {
        sym = mdVal.getValue();
    }

    @Override
    public void visit(MDGlobalVariable mdGlobal) {
        mdGlobal.getVariable().accept(this);
    }

    @Override
    public void visit(MDGlobalVariableExpression md) {
        md.getGlobalVariable().accept(this);
    }
}
